FIRES IN AIRPLANE HANGARS TEST METHODS OF CONTROL
Report of a Fact-Finding Committee of U. S. Department of Commerce-Description of the Experiments-List of the Findings
A WOODEN hangar has successfully weathered a series of seven fire tests made by a special Fact-Finding Committee organized by the Aeronautics Branch of the U. S. Department of Commerce, to determine the effectiveness of automatic application of water in controlling airplane hangar fires. The report of the committee covers the circumstances and gives the results and conclusions of the tests which were conducted in Washington with obsolete airplanes in a regulation-size lumber hangar.
While these tests were not considered exhaustive they covered a wide range of likely fire origins, a variety of risks respecting plane storage and inflammable material present. Four types of sprinkler installations were used for applying water, viz: dry-pipe; wet-pipe; open overhead sprinklers, with heat-actuated water-supply valve releasing mechanisms; and open overhead sprinklers of the same type and floor spray nozzles with heat-actuated water-supply valve releasing mechanisms. Every effort was made to set up conditions that would make up in intensity for any limitations in variety in character of fire origin or hazard increasing circumstances.
The committee’s conclusions are carefully worded to avoid assuming more than could be reasonably deduced from the specific tests. Graphic illustrations of the report, on the other hand, showing several instances in which the interior of the hangar was filled with a bank of intense flame, give vivid testimony of the effectiveness of the sprinklers in these specific instances in bringing the fire under control without material damage to the hangar.
The findings of the Committee, eleven in number, read:
- Slow-burning: fires in well ventilated buildings with high ceilings may continue without opening automatio sprinklers.
- Extremely fast fires in single planes may burn themselves out without opening automatic sprinklers.
- Fires in readily ignitable and highly combustible materials spread over wide areas, such as gasoline on the floor or highly inflammable wing surfaces, may proceed at first faster than the opening of sprinklers and thus outrun for a time the application of water to the fire.
- Water form overhead sprinklers may on some occasions keep the top surfaces of an airplane wetted, thus presrving a shelter under which a fire may spread to various parts of the machine. Under this condition, supplemental equipment, such as hand extinguishers or hose streams, could be brought into use effectively. The use of floor sprinklers might reduce the spread of fire. None of these should be permitted to deprive overhead sprinklers of the water necessary for their effective operation.
- Each sprinkler installation should be equipped with suitable alarm devices in order that additional fire-fighting appliances may be on hand as promptly as possible.
- Fires involving large quantities of gasoline or similar fuel may not be entirely quenched by sprinklers alone, but would be kept, usually, is a subdued condition, making possible close approach thereto with other means for their subjucation. Suitable additional extinguishing devices should be provided to supplement sprinkler systems for quenching these or similarly persistent fires.
- Fires in which several airplanes are ignited simultaneously will usually result in the burning of surface fabrics and the ruin or destruction of some of the structural members of all involved, and may damage airplanes closely adjacent to them.
- Fire igniting a single airplane, even under highly favorable conditions for quick spread throughout the machine, is usually controlled by sprinklers so as to cause little or no damage to other airplanes stored close to the one first ignited.
- The automatic application of water by sprinklers will generally give good protection to airplane hangars and contents except such of the contents as are involved in the outbreak of the fire.
- The advantages of a heat-actuated system of open sprinklers, such as the one tested are apparent (a) in small spreading fires (b) in buildings having high ceilings or conditions of ventilation causing horizontal drafts, or (c) in those fires where the time required for the opening of automatic sprinklers permits the fire to burn out or to get beyond the range of discharging sprinklers.
- These tests have indicated that sprinkler systems installed and maintained in accordance with recognized good practice for the protectfon of this class of property, and having an adequate water supply, can control most of the fires likely to occur in airplane hangars: therefore serious thought, including thorough economic consideration should be given to the subject of such installations wherever commercial air transport or other aerial activities are carried on.
The tests were naturally of a highly spectacular character. In one instance more than three hundred gallons of gasoline was at risk including gasoline spilled on the floor and wings of four planes and in fuel tanks. In some of the tests were saturated with gasoline, gasoline was spilled on the floors or allowed to leak from tanks, gasoline and oil saturated rags were used to convey flames, and a highly inflammable treating “dope” was spread over the wings. In one instance flames leaped through the front door of the hangar to a height of approximately 50 feet. Several times the hangar was filled with what seemed a solid bank of flame and on one occasion flames licked at the roof and a roof truss member for a considerable period of time.
The hangar was of wood construction approximately 80 feet by 66 feet by 28 feet high. It was donated by the National Committee on Wood Utilization of the Department of Commerce. The National Automatic Sprinkler Association furnished both overhead and ground sprinkler installations and an elevated water supply tank. The Bureau of Standards furnished technicians and observers for conduct of the tests and scientific instruments for recording data during the course of the fires.
Harry H. Blee, Director of Aeronautic Development, Department of Commerce served as Chairman of the FactFinding Committee. Included in its membership were representatives of the Army and Navy air services, the U. S. Bureau of Standards, the National Advisory Committee for Aeronautics, the Aeronautical Chamber of Commerce, the National Automatic Sprinkler Association, the National Board of Fire Underwriters, and the Underwriters Laboratories.
Firemen of Bellingham to Have Pay Reduced-The Council of Bellingham, Wash., voted to reduce the salaries of members of the Fire Department and other city employees in order to meet a deficit of $25,734 in the estimated receipts of the general fund. The Council voted for a reduction in wages rather than decrease the personnel.